From bf5ad82b3c3589d3aa0674f87d47668079dbc81d Mon Sep 17 00:00:00 2001
From: Guillaume Martres <smarter@ubuntu.com>
Date: Tue, 25 Apr 2017 12:05:07 +0200
Subject: [PATCH] Only recreate dotty-compiler jar if it changed

Previously `dotty-compiler/packageBin` always recreated the jar because
we overwrote the compiler.properties ressource file.
---
 project/Build.scala | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/project/Build.scala b/project/Build.scala
index abe8f52deb52..1851ba2a3a29 100644
--- a/project/Build.scala
+++ b/project/Build.scala
@@ -275,7 +275,11 @@ object Build {
       resourceGenerators in Compile += Def.task {
         val file = (resourceManaged in Compile).value / "compiler.properties"
         val contents = s"version.number=${version.value}"
-        IO.write(file, contents)
+
+        if (!(file.exists && IO.read(file) == contents)) {
+          IO.write(file, contents)
+        }
+
         Seq(file)
       }.taskValue,